Dermatology Flashcards
What are the 4 layers of the skin from superficial to deep?
Epidermis
Basement Membrane Zone
Dermis
Subcutaneous layer
What are the 4 layers of the epidermis from superficial to deep?
Keratin layer
Granular layer
Prickle Cell layer
Basal layer
What do keratinocytes do?
Secrete a variety of cytokines in response to tissue injury or disease
In what layer are melanocytes found in?
Basal layer
Where does the epidermis originate from?
Ectoderm
What are the downward projections into the dermis from the epidermis called?
Rete Ridges
What are the 2 components of the epidermal cytoskeleton?
Keratin filaments
Desmosomal proteins
Which epidermal layer creates the semi-permeable skin barrier
Granular layer
What is the name of the skin cells which lose their nucleus in order to become surrounded by an inpermeable, protein envelope?
Stratum corneum cells
What types of immune molecules are involved in the innate immune system of the skin?
Netrophils, macrophages and keratinocytes
What can a deficiency in the skin’s innate immune system cause?
Atopic eczema
What is the role of melanocytes in the skin?
UV protection
Where are Merkel cells found?
Basal layer
What is the role of Merkel cells?
play a role in sensation esp. on fingertips and in the oral cavity
What are Langerhans cells?
Dendritic cells in the supra-basal layer; antigen presenting cells
What is the other name for the Basement Membrane Zone?
Dermo-epidermal junction (DEJ)
What does the basement membrane zone consist of?
Many types of collagen
Hemidesmosomal proteins
Integrins
Laminin
What is the role of the DEJ?
keeps the dermis and epidermis firmly attached
What can protein deficiencies in the DEJ cause?
Fragility of skin and a number of blistering diseases
Where does the dermis originate from?
Mesoderm
What does the dermis contain?
Blood, lymphatics, nerves, muscle
What is the dermis made of?
Collagen and Elastin in a ground substance
Where is the only surface Eccrine sweat glands are not found?
Mucosal surfaces
Where are the apocrine sweat glands found?
Axillae, anogential area, and scalp
What is the function of the sebaceous glands?
Secrete sebum (grease) onto the skin surface via the hair follicle - after puberty
How does hair form?
Downgrowth of epidermal keratinocytes into the dermis
What are the different parts of a hair shaft?
Inner and outer root sheaths, cortex, medulla
What are the 3 types of hair?
Terminal - scalp, beard, pubic
Vellus - fine downy hair on women’s faces and prepubescent children
Lanugo - Soft hair covering newborns (esp those premature)
What does the lower portion of the hair follicle consist of?
Expanded bulb (contains melanocytes), which surrounds a dermal papilla
What are the 3 stages of the hair growth cycle?
Anagen - growth phase
Catagen - involution phase
Telogen - Shedding phase
What causes hair to go grey?
decreased tyrosinase activity is hair bulb melanocytes
What causes hair to go white?
Total loss of melanocytes
What are nails?
Tough plates of hardened keratin
Where does nail growth arise from?
Nail matrix
What constitutes the subcutaneous layer?
Adipose tissue, blood vessels and nerves
Where do melanocytes originate from?
Neural crest
At what stage does a foetus have fully developed skin and hairs?
26 weeks
Histologically how is the epidermis described?
Stratified squamous epithelium
Histologically what is the basal layer made up of?
Once cell thick cuboidal cells
Intermediate filaments
What is the prickle cell made up of?
Polyhedral cells
Desmosomes
Keratohyalin granules
What does the keratin layer consist of?
Corneocytes
Keratin
Filaggrin
What is special about the cells of the oral mucosa?
Keratinised to deal with friction and pressure
What is special about the cells of the occular mucosa?
Lacrimal glands
Eye lashes
Sebaceous glands
Where do Melanocytes migrate from and to?
From the neural crest to the epidermis
What are melanocytes and where are they found?
Pigment-producing dendritic cells
In and above the basal layer
What colour is Eumelanin?
Brown or black
What colour is phaeomelanin?
Red/yellow
Where do Langerhans cells originate from?
Mesenchymal cells (bone marrow)
Where are Langerhan’s cells found?
Prickle cell layer (also dermis and lymph nodes)
How are Langerhans cells characterised histologically?
By Birbeck granules (they look like sports raquets)
Where are Merkel cells found?
Basal layer (between keratinocytes and nerve fibres)
What type of cell are Merkel cells?
Mechanoreceptors
What is dermographism?
Skin becomes raised and inflamed when stroked or scratched etc.
What causes dermographism (dermatographic urticarial)
Mast cells release histamines in the absence of antigens, due to their weak membranes
What can the sun do to the skin on a microscopic level?
Solar elastosis - elastin filaments break up and cause the skin to wrinkle
What receptors in the skin sense pressure changes?
Pacinian Corpuscles
What receptors in the skin sense vibrational changes?
Meissners Corpuscles
Under a microscope what do Pacinian Corpuscles look like?
sliced onion
Sebaceous glands are dormant at birth, when do they become active?
Puberty
What do sebaceous glands do?
Produce sebum to control moisture loss and to protect from bacterial and fungal infection
What causes acne?
Increased sebum production, blocked ducts and bacterial activity
Where would you find apocrine sweat glands?
Axillae and perineum
What do apocrine sweat glands do?
Produce an oily fluid which produces an odour after bacterial decomposition
What are apocrine sweat glands dependent on?
Androgens
Where do you find Eccrine sweat glands?
Whole skin surface; esp. palms, soles and axillae
What is the nerve supply to the eccrine sweat glands?
Sympathetic cholinergic nerve
What is the role of the eccrine glands?
Ultrafiltration of fluids
cooling by evaporation
Moistening palms and soles to aid grip
Give 2 examples of conditions considered as acute skin failure.
Toxic Epidermal necrolysis
Erythroderma
What to metabolic processes is the skin heavily involved in?
Vitamin D metabolism - Uv absorbed in skin helps in vit D metabolism
Thyroid Hormone metabolism - is 1 located of where T4 is converted to T4
What cells are important in the skin’s immune function?
Langerhan’s cells
T-Cells
What is impetigo?
A highly infectious skin disease which is most common in children
How does impetigo present clinically?
Weeping, exudative areas with a honey-coloured surface crust
How is impetigo spread?
Direct contact
What organisms can cause impetigo?
Staph
Group A beta-haemolytic strep
If impetigo is caused by a Staph infection, how is it treated?
Oral antibiotics (7-10 days) Flucloxacillin 500mg 4xdaily
If impetigo is caused by a Strep infection, how is it treated?
Phenoxymethylpenicillin 500mg 4xdaily (7-10 days)
If impetigo doesn’t respond to initial treatment what should then be done?
Nasal swabs taken
Nasal mupiocin 3xdaily (1 week) to eradicate nasal carriage
Staph infections can rarely release exfoliating toxins which act high up in the epidermal layer. What effects does toxin A produce if it is released?
Blistering at the infection site - bullous impetigo
Staph infections can rarely release exfoliating toxins which act high up in the epidermal layer. What effects does toxin B produce if it is released?
Staph Scalded Skin Syndrome (SSSS) - more widespread blistering
What groups are more at risk of developing SSSS?
Children
Immunosuppressed adults
Adults with renal disease
How are toxic infections released from Staph infections treated?
Flucloxacillin (with supportive care)
What is cellulitis?
A hot, tender area of confluent erythema due to deep subcut. infection (occasional blistering)
Where does cellultis often affect?
Lower leg (upward spreading)
What general symptoms will a patient with cellulitis have?
Generally unwell with a fever
What causes cellulitis?
Beta haemolytic strep or staph (rare)
Immunosuppressed/diabetic patients may develop gram -ve or anaerobic infection
How is cellulitis conformed/organism identified?
Serology
How is cellulitis treated?
Phenoxymethylpenicillin (or erythromicin) and flucloxacillin 500mg 4xdaily
What is ecthyma?
Chronic, well-demarcated, deeply ulcerative lesions (sometimes with an exudative crust)
What causes ecthyma
Strep or Staph infection
Ecthyma is rare in the UK, but what groups of patients may develop it?
IVDUs and HIV patients
What is the treatment for ecthyma?
Erythromicin PO 500mg 4xdaily for 7-10 days
What is erythrasma?
Orange-brown flexural rash - often seen in axillae or toe web spaces
What causes erythrasma?
Corynebacterium minutissimum
How does erythrasma appear under Wood’s light?
Coral pink fluorescence
How is erythrasma treated?
Erythromicin PO 500mg 4xdaily for 7-10 days
What is folliculitis and how does it present?
Inflammation of the hair follicle which presents with itchy, tender papules
What is the commonest causative organism of folliculitis?
Staph aureus
What is the treatment for folliculitis?
topical antiseptics and either topical or oral antibiotics
What are furuncles?
(Boils) are deep seated infections of the skin which present as painful, red swellings
What causes furuncles?
Staph infection
What should be done to ensure MRSA is not the cause of a furuncle?
Swabs for antibiotic sensitivities
How are furuncles treated?
Erythromicin 500mg 4xdaily for 10-14 days
Antiseptics (chlorhexidine) can be useful as prophylaxis
What is hidradentis suppurativa?
A painful, discharging, chronic inflammation in areas rich in apocrine glands of which there is no known cause
How is hidradentis suppurativa treated?
Weight loss, antibiotics and oral retinoids
What is pitted keratolysis?
A superficial infection of the horny layer of the skin caused by a corynebacterium
How does pitted keratolysis present?
On soles of feet with numerous, small, punched out lesions on a macerated (prune-like) skin
How is pitted keratolysis treated?
Topical antibiotics and anti-sweating lotions
How does leprosy present?
Rare in UK
Usually involves skin and the features depend on an individuals immune response to Mycobacterium leprae
What skin manifestations of TB are there?
Lupus vulgaris
Tuberculosis verrucoa cutis
Scrofuloderma
The tuberculides
What is viral exanthem?
The commonest type of viral-induced rash which presents as a widespread nonspecific erythamatous maculopapular rash.
What causes viral exanthem?
Circulating immune complexes of antibody + viral antigen localising to dermal blood vessels
What is Slapped Cheek Syndrome, and what causes it?
A rash across the face which can occur for weeks-months which is caused by Human Erythrovirus B19
Patient is generally well throughout and after the facial rash has cleared a lacy, macular rash appears on the body
Most people are affected by HSV1 in childhood and the majority have subclinical infection. If not however, how does this present?
Clusters of painful blisters on the face (esp around the mouth)
If HSV1 reccurs, how does it present?
Usually as cold sores
What does HSV2 infection typically cause?
Genital herpes
How is HSV infection treated?
Oral aciclovir 500mg 2xdaily for 5 days
Cold sores can be treated with topical aciclovir creams
What 2 diseases does varicella zoster virus cause?
Chicken pox - Varicella component
Shingles - Zoster componenet
How does chicken pox present?
Generlised itchy rash and fever
What complications can arise from chicken pox?
secondary infection pneumonia haemorrhagic rash scarring encephalitis (brain tissue swelling)
How is chicken pox treated?
It isn’t usually - self limiting process
Infection = immunity in most cases
What causes shingles?
Reactivation of the virus, usually in older age in a dermatomal pattern
How does shingles present?
Preceded by a tingling sensation or pain
This is followed by a painful, tender, blistering erruption which occur in crops, become pustular and then crust over
How long does a shingles rash typically last for?
2-4 weeks
What complications can arise from shingles?
Severe, persistant pain
Others depending on the dermatome affected
How is shingles treated?
Analgesia and antibiotics (if secondary bacterial infection)
Valaciclovir1g or famciclovir 250mg 3xdaily for 7days (shortens attacks)
What does HPV cause relating to the skin?
Viral Warts
What are common HPV warts?
Papular lesions with a course, roughened surface often seen on the hands and feet.
They have small black dots (bleeding points)
How do HPV common warts spread?
Direct contact
What is another name for plantar warts caused by HPV?
Verrucae
What are plane warts?
Less common lesions caused by only certain types of HPV. Are very small, flesh coloured/pigmented and flat topped.
Where are plane warts typically found?
Face or backs of hands - usually in multiples
How are warts caused by HPV treated?
almost always resolve spontaneously
Topical keratolytic agents can speed up the healing process
Cryotherapy may also be helpful but it does have side effects
What is molluscum contagiosum?
A common cutaneous infection in childhood causing multiple small translucent papules which are solid to touch
What causes molluscum contagiosum?
The pox virus
How is molluscum contagiosum spread and how long does infection last?
Direct contact
6-12 months
What is orf?
A pox virus disease of sheep which can be spread to humans via direct contact
How does orf present?
1-2cm reddish papule with a surrounding erythema which usually becomes pustular
What is tinea corporis?
A dermatophyte fungal infection of the body
How does tinea corporis present clinically?
Asymmetrical scaly patches with central clearing and an advancing, scaly raised edge.
What is tinea faciel?
A dermatophyte fungal infection of the face
How does tinea faciel present?
Often occurs after topical steroid use
Erythematous, slightly scaly lesions
Itchy after sun exposure
What is tinea cruris?
A dermatophyte fungal infection of the groin
How does tinea cruris present?
Well-demarcated, red plaques with arc like borders, extending down from the upper thighs
What is tinea pedis?
A dermatophyte fungal infection of the feet
How does tinea pedis present?
Infection mainly in the toe clefts with white, macerated and fissured lesions
What is tinea manuum?
A dermatophyte fungal infection of the hands
How does tinea manuum present?
A diffuse, erythematous scaling of the palms and backs of hands
Variable skin peeling and thickening
What is tinea capitis?
A dermatophyte fungal infection of the scalp
How does tinea capitis present?
From a mild diffuse scaling with no hair loss, to scaly patches with associated alopecia.
May present with a few pustules with exudate
What is tinea unguium?
A dermatophyte fungal infection of the nails
How does tinea unguium present?
An asymmetrical discoloration of 1 or more nails
Nail plate appears thickened and a crumbly white material appears under it
What is tinea incognito?
A fungal skin infection modified by topical steroid use
How does tinea incognito present?
Variable - non-specific erythema or a few reddish nodules with a little scaling. Rash improves with steroids but gets and spreads when treatment is stopped
What is the treatment for all tinea infections?
Body of flexures = topical antifungals Widespread = oral antifungals Toenails Itraconazole (antifungal) for 3-6 months
What is Candida albicans?
An opportunistic yeast that thrives in warm and moist environments
How would a candida albicans infection present?
A superficial white/creamy psuedomembranous plaque which can be scraped off leaving raw areas underneath.
Satellite lesions may also be found
How is a candida albicans infection treated?
Topical antifungal creams
Nail infections need systemic antifungal therapy
What is pityriasis versicolour?
An overgrowth of the normal bacterial skin flora or pityrosporum
How does pityriasis versicolour present?
In white people - reddish-brown scaly lesions on the trunk
In black people - macular areas of hypopigmentation
How is pityriasis versiolour treated?
Slenium sulphide or 2% ketoconazole shampoo or topical imidazole cream
What is seborrhoeic eczema?
A pityrosporum folliculitis
How does seborrhoeic eczema present?
Small itchy papules on the upper back, centered on the hair follicles (common in young adult males)
How is seborrhoeic eczema treated?
ketoconazole shampoo or topical imidazole cream
What is scabies?
An intensely itchy rash caused by the sarccoptes scabies mite
How does scabies present?
Itchy red papules anywhere on the skin
Sometimes liner or curved burrows can be seen
Itch is usually worse at night
What complications can arise from scabies?
Excoriations
Secondary bacterial infections
How is a diagnosis of scabies confirmed?
Skin scrapings and examining a potassium hydroxide preparation by microscopy for the mites and/or eggs
How is scabies treated?
Topical scabicide is applied and washed off after 10 hours (all skin below the neck)
In under 2s treat head and neck aswell
All close contacts should be treated even if they are asymptommatic
How does crusted (Norwegian) scabies differ from regular scabies?
Occurs in immunospressed people where huge numbers of mites are carried. It is not always itchy but is extremely effective.
How does Norwegian scabies present?
Hyperkeratotic crusted lesions
May progress to widespread erythema with irregular crusted plaques.
How is Norwegian scabies treated?
Careful barrier nursing
Repeated applications of a scabicide
Oral invermectin
What are lice?
Blood sucking ectoparasites that can affect humans in 3 ways.
How do headlice present?
Itch
Scalp excoriations
Papules on the neck
How are headlice diagnosed?
The presence of eggs stuck to the hair shaft
How are headlice treated?
eradication difficult due to non-compliance and resistance
Malathion, carbaryl and phenothin are the most commonly used agents (insecticides)
How do body lice present clinically?
Itch
Excoriations
post-inflammatory hyperpigmentation of the skin
Infestation of poverty and neglect
How should body lice be treated?
malathion/permethrin for patient and high temp washing and drying of clothing
How do pubic lice present?
Itching esp. at night
How are pubic lice treated?
Malathion, carbaryl and phenothin are the most commonly used agents (insecticides)
How do arthropod-borne diseases (insect bites) preset?
itchy urticated lesions, often grouped in clusters
How can eczema present histologically?
A collection of fluid in the epidermis between keratinocytes (spongiosis) and an upper dermal peri-vascular infiltrate of lymphohistiocytic cells
How can chronic eczema present histologically?
marked thickening of the epidermis (acanthosis)
What is the prevalence of atopic eczema?
Common - upto 5% of UK
10-20% children
What is the initial pathophysiological process of atopic eczema?
Selective activation of Th2CD4 lymphocytes driving the inflammatory processes
What cells predominate the chronic phase of atopic eczema?
Th0 and Th1
What immunoglobulin is raised in 80% of patients with atopic eczema?
IgE
What is fillagrin?
An epidermal barrier protein
How is it thought that having a mutation in the filaggrin gene can predispose an individual to atopic eczema?
Mutations can cause ichthyosis vulgaris which can predispose Caucasians to atopic eczema.
What things may exacerbate atopic eczema?
Infections Lack of infant infection Chemicals/detergents Teething, stress, anxiety Cat + dog fur Foods and house mites
How does atoptic eczema most commonly present?
Itchy, erythematous, scaly patches esp. in flexures
Where does atopic eczema start in infants?
Head and face
What differences may acute lesions in atopic eczema show?
Weeping or exudate and small v present?esicles
What ca a chronic scratching in atopic eczema lead to?
Lichenification with exaggerated skin margins
In patients with pigmented skin, how would atopic eczema present?
Extensor involvement
May be papular or follicular in nature
Post-inflammatiry hyper or hypo pigmentation may occur and this is usually very slow to resolve
Other than the itchy lesions associated with atopic eczema, how else may it affect the skin?
Upper arm and thigh skin may feel roughened due to follicular hyperkeratosis
Palms have prominant skin creases
May be a dry fish-like scaling on lower legs (ichthyosis vulgaris)
If a patient with atopic eczema gets a secondary infection on some lesions, what is the causative organism most likely to be?
Staph aureus
How would a secondary infection of staph aureus to atopic eczema present?
Crusted, weeping, impetigo-like lesions
Why are cutaneous viral infections widespread when they infect atopic eczema lesions?
Due to sratching
If HSV infects areas of atopic eczema, what is this condition called?
eczema herpeticum
How does eczema herpeticum present?
Multiple, small blisters or “punched-out” crusted lesions associated with malaise and pyrexia
How is eczema herpeticum treated?
Rapid oral or IV aciclovir
What signs can appear in the eyes of somebody with atopic eczema?
Conjunctival irritation
keratoconjunctivitis
Cataract
If a child has chronic-severe atopic eczema what clinical sign may become apparent as they grow older?
Retarded growth (nothing to do with steroids!!)
How is atopic eczema diagnosed?
Clinically based on examination and history
How is the atopic part of atopic eczema diagniosed?
High serum IgE or high specific IgE to antigens
Also blood eosinophilia in 80% patients
If a patient has atopic eczema as a child, what are the chances it will spontaneously resolve before they reach their teenage years?
80-90%
What general lifestyle measures can be used to treat atopic eczema?
Avoiding irritants
Cotton clothing
Avoiding overheating
Potentially avoiding dairy and eggs in the under 1s
What is the commonly used triple therapy of topical agents used to treat atopic eczema?
Topical steroid
Frequent emolients
Bath oil and soap substitutes
What potency of steroids should be used on the face in atopic eczema?
ONLY mild steroids
What potencies of steroids may be used on the body in a patient with atopic eczema?
Mild
Moderate
Diluted potent
Potent and very potent steroids may need to be used on what body areas in atopic eczema?
Palms and soles (thicker skin)
What topical immunomodulators can be used in the treatment of atopic eczema in individuals >2y/o?
Tacrolimus ointment
Pimecrolimus cream
When using immunomodulators for atopic eczema, what should patients avoid?
Sun exposure
Vaccines
In patients with atopic eczema what sedating antihistamine may be used at night time?
Oral hydroxyzine hydrochloride
Paste bandaging can be useful in atopic eczema with what features?
Resistant or lichenified
What second-line agents can be used in atopic eczema esp. if the symptoms are affecting the patients day to day living?
UV phototherapy
Prednisolone
Ciclosporin
Azathioprine
What does ciclosporin do within the immune system?
Inhibits IL2 production by T cells
Is ciclosporin sfae for use in pregnancy?
NO!
How does discoid (nummular) eczema present?
Well-demarcated, scaly, patches esp on limbs
Atopic eczema follows a rather chronic pattern, what pattern does discoid eczema follow?
Acute/subacute often with an infective component (Staph. aureus)
How does hand eczema present?
Itchy vesicles or blisters on the palms and sides of fingers.
Diffuse erythematous scaling and hyperkeratosis of palms
Scaling and peeling of skin esp. at fingertips
What investigation should be performed in individuals with hand eczema as 10% will have a +ve result?
Patch testing
What is seborrhoeic eczema?
An overgrowth of pityrosporum ovale and a strong cutaneous immune response to yeast
Affects body areas rich in sebaceous glands
How does seborrhoeic eczema present in general?
Inflammation and scaling
What conditions is seborrhoeic eczema more likely to occur in?
Parkinsonism and HIV
What 3 groups of people are most often affected by seborrhoeic eczema?
Neonates
Young adults (esp. males)
Elderly
How does seborrhoeic eczema present in neonates?
Yellowish thick crusts on the scalp (cradle cap)
More widespread erythematous, scaly rash over the trunk (esp. nappy area)
There is little pruritus
Improves spontaneously over a few weeks
How does seborrhoeic eczema present in young adults?
More persistent rash than in neonates
Erythematous scaling along sides of nose, eyebrows, around the eyes and extending into the scalp
May cause inflammation of the eyelid (blepharitis)
May affect skin over sternum, axillae, groins and glans penis
How does seborrhoeic eczema present in the elderly?
Widespread inflammation and scaling and potentially causing erythroderma
What is erythroderma?
Erythema and scaling affecting nearly the entire skin surface
How is seborrhoeic eczema treated?
Mild steroid ointment and a topical antifungal
Emolients and a soap substitute are useful adjuncts
What treatments can be used for seborrhoeic eczema on the scalp?
Ketoconazole shampoo and arachis oil
What is venous (stasis) eczema?
Eczema which occurs alongside chronic venous hypertension and slow movement of blood in the lower limbs
Who is venous eczema most likely to affect?
Older patients esp. women and those with a PMH of venous thrombosis or previous varicose vein surgery.
How does venous eczema present?
Brownish pigmentation (due to haemosiderin) in the skin, potentially ulceration or varicose veins Superimposed contact eczema usually due to allergic reactions to the topical therapies used.
If a leg ulcer is resistant to treatment, what test should ALWAYS be done?
Patch testing to the agents used
How is venous eczema treated?
Emollients and a moderately potent to potent topical steroid
Support stockings/compression bandages and leg elevation to improve the underlying venous hypertension
Where and when does asteatotic eczema commonly affect?
Lower legs and backs of hands esp. in winter
How does asteatotic eczema present?
Dry, plate-like cracking of the skin with a red, eczematous component.
How is asteatotic eczema treated?
Avoidance of soaps
Regular emollient and bath oil use
If skin is v. inflammed then a mild topical steroid can be used
What presentation of eczema would make you think it could be allergic/irritant contact eczema?
An unsual or localised distribution esp. if there is no FH of atopy.
Also an exaccerbation within the workplace
By what 2 mechanisms can allergic/irritant contact eczema arise?
Direct irritation
Type IV delayed hypersensitivity
What are the common agents to cause allergic contact eczema?
Nickel Chromate Latex Perfumes Plants
What is the usual culprit in irritant contact eczema?
Occupational irritants
How is allergic/irritant contact eczema treated?
As for atopic eczema
Strict avoidance of any causative agent
What is photosensitive eczema?
A relatively rare condition where eczema occurs in exposed areas in response to sunlight.
How does photosensitive eczema present?
Typical eczema features and marked skin thickening.
Histologically hoe does photosensitive eczema present?
Atypical cellular structure which may appear lymphoma-like
How is photosensitive eczema diagnosed?
Using special monochromator light testing
How is photosensitive eczema treated?
Avoidance of sunlight
Topical steroids + emollients in mild cases
Oral prednisolone in more severe cases
Azathioprine for long term immunosuppression
Low-dose phototherapy may desensitise an individual to the condition
What is Lichen simplex?
A disorder characterised by chronic scratching or rubbing in the absence of an undrlying dermatosis
How does lichen simplex present?
Thickened, scaly, hyperpigmented areas of lichenification
Starts as intense itching, and becomes more tender as the rubbing/scratching continues
Itch-scratch cycle
What body sites does lichen simplex commonly affect?
nape of neck Lateral calves upper thighs upper back scrotum vulva
What body sites does lichen simplex commonly affect?
nape of neck Lateral calves upper thighs upper back scrotum vulva
What is nodular prurigo?
Similar to lichen simplex but has a different cutaneous response to scrtaching/rubbing
How does nodular prurigo present?
Individual, itchy papules and domed nodules esp. on teh upper trunk and extensor surfaces of limbs
What can predispose an individual to either lichen simplex or nodular prurigo?
Being Asian, Black African or Oriental
Atopic history
Emotional stress
How are lichen simplex and nodular prurigo treated?
Very potent topical steroids with occlusive tar bandaging
Immunosupression for v. resistant cases
Phototherapy may also be of benefit
What is psoriasis?
A common papulo-squamous disorder characterised by red, well-demarcated, scaly patches
When does psoriaris commonly present?
In 16-22 y/os (commoner)
55-60 (late onset)
What is the aetiology behind psoriasis?
Polygenic + environmental
Evidence suggests a T-cell driven disorder to unidentified antigens
Briefly explain the pathogenesis behind psoriasis.
Trigger factors activate dendritic cells, which produce Th1 and Th17.
These secrete mediators to act on keratinocytes to release chemokines, cytokines etc.
These maintain the inflammation and feedback to the dendritic cell.
This results in upregulation of Th1-type T-cell cytokines, growth factors and adhesion molecules.
What does psoriasis show on histology?
Epidermal acanthosis and parakeratosis
Granular layer often absent
Rete ridges are elongated and clubbed
Capillary dilatation surrounded by a neutrophilic and lymphohisteocytic perivascular infiltrate
What does psoriasis show on histology?
Epidermal acanthosis and parakeratosis
Granular layer often absent
Rete ridges are elongated and clubbed
Capillary dilatation surrounded by a neutrophilic and lymphohisteocytic perivascular infiltrate
What drugs can worsen the presentation of psoriasis?
Lithium
Beta blockers (rare)
Anti-malarials
How does chronic plaque psoriasis present?
Pink/red scaly patches with a silver scale
Extensor surfaces, lower back, ears and scalp are commonly affected
Lesions can become itchy or sore
What it Kobner’s phenomenon?
New lesions appear at sites of skin trauma (psoriasis and other conditions)
How does flexor psoriasis present?
Tends to arise in later life
Well-demarcated, red glazed plaques confined to the flexures (no scaling)
Often misdiagnosed as a candidal infection (but candida has satellite lesions)
How does guttate psoriasis present?
‘Raindrop-like’ psoriasis seen in children and young adults
Explosive eruption of very small ovular/circular plaques appear on the trunk about 2 weeks after a strep sore throat
How do erthyrodermic and pustular psoriasis present?
Most severe type representing a widespread intense inflammation of skin
Can occur together (Van Zumbusch) psoriasis
May be associated with malaise, pyrexia and circulatory disturbance
Pustules are not infected but rather sterile collections of inflammatory cells
What nail changes can occur with psoriasis?
Pitting of nail plate
Distal separation of nail plate (onycholosis)
Yellow-brown discolouration
Sublingual hyperkeratosis
What percentage of psoriasis sufferers will develop psoriatic arthritis?
5-10%
What percentage of psoriasis sufferers will develop psoriatic arthritis?
5-10%
How is chronic plaque psoriasis treated?
Emollients - hydration Mild-moderate topical steroids Vit D3 analogues Retinoids Purified coal tar Salicyclic acid
What risk can occur with overuse of Vit D3 analogues?
Hypercalcaemia
What are the problems with dithranol being used to treat psoriasis?
Irritates normal skin
Difficult to apply at home
What can either dithranol or coal tar be combined with to give 75% clearance rates at 6 weeks?
UVB or PUVA therapy
How is flexural psoriasis treated?
Mild steroids and/or topical tar creams
Calcitrol (Vit D3 analogue) and 0.1% tacrolimus can be used where irritation is an issue
How is guttate psoriasis treated?
Topical therapies and/or UVB phototherpy
How is palmo-plantar psoriasis treated?
Very potent topical steroids, coal tar paste or local had/foot PUVA
Immunosupressive agents can be used in more resistant cases
How is palmo-plantar psoriasis treated?
Very potent topical steroids, coal tar paste or local had/foot PUVA
Immunosupressive agents can be used in more resistant cases
How is erythrodermic psoriasis treated?
Systemic therapy but not phottherapy
Methotrexate
Cytokine modulators
How can the severe nausea associated with methotrexte use be lessened?
Folic acid
What regular blood tests need to be done in methotrexate use?
Monitoring for bone marrow suppression
Monitoring for liver damage (hepatic fibrosis)
What should be avoided in methotrexate use?
Alcohol
NSAIDs
What is the prognosis for patients with psoriasis?
esp guttate psoriasis
Most will have disease for life but 80% will have periods of remission
Severity fluctuates
Guttate psoriasis resolves spontaneously and a third will not get recurrence. The other 2/3 will get recurrent attacks or go on to develop chronic plaque psoriasis
What is urticaria?
A common skin condition characterised by acute development of itchy wheals or swellings in the skin due to leaky dermal vessels.
What is angio-oedema?
Similar to urticaria but involves sub-dermal vessels rather than dermal vessels
What is the pathogenesis behind urticaria?
Degranulation of cutaneous mast cells releases inflammatory mediators incl. histamine
This creates the dermal and sub-dermal vessel leakiness
Most cases have an underlying AI cause
What factors can contribute to an individual developing urticaria?
Secondary to infection, drug reactions, food allergy or SLE (rare)
Atopic history
Children and young adults - usual age of presentation
In heriditary angio-oedema and ACEI-induced angio-oedema; histamine is not the key mediator. What is?
Bradykinin
How does urticaria commonly present?
Cutaneous swellings or wheals developing over minutes
Can occur for minutes-hours before resolving spontaneously
Anywhere on body
Lesions are intensely itchy
Normally lesions are erythematous
How does urticaria commonly present?
Cutaneous swellings or wheals developing over minutes
Can occur for minutes-hours before resolving spontaneously
Anywhere on body
Lesions are intensely itchy
Normally lesions are erythematous
How does angio-oedema commonly present?
Soft tissue swelling esp. around eyes, lips and hands
Rarely itchy
Dangerous if mouth/larynx involved - thankfully this is rare
What is a physical urticaria?
Urticaria caused by a physical stimuli e.g. cold, pressure, water, chemicals etc.
How does cholinergic (stress/heat) urticaria present?
Small itchy papules appear on the upper trunk
Common
How does delayed pressure urticaria present?
Deep swellings some hours after pressure has been removed (e.g. tight belt)
Rare
What investigations are done for urticaria/angio-oedema?
History - most useful
Routine investigations are unjustified unless history suggests a clear cause
How are urticarias/angio-oedema treated?
Underlying causes if identified should be treated
Avoidance of salicylates and opiates as they cause further mast cell degranulation
Oral antigistamines useful in idiopathic cases
If resistant to antihistamine therapy - H2 bloker or dapsone may be used
If angio-oedema is affecting the mouth/throat what treatment is required?
Urgent IM adrenaline and IV steroids
What is the general prognosis for urticarias?
Most idiopathic cases disappear spontaneously with the majority controlled by antihistamines
Physical urticarias are more persistent and more resistant to therapy
What is urticarial vasculitis and when should it be suspected?
A urticaria varient
If individual lesions last >24h and leave bruising then suspect
What symptoms are associated with urticarial vasculitis?
Arthralgia or myalgia
Small % may go onto develop an AI rheumatic disease
How is urticarial vaculitis diagnosed?
Skin biopsy
What investigations should be done in urticarial vasculitis?
Full vasculitis screen for an underlying cause
How is urticarial vasculitis treated?
Antihistamines
Oral Dapsone
Immunosuppressants
How is urticarial vasculitis treated?
Antihistamines
Oral Dapsone
Immunosuppressants
What is lichen planus?
A pruritic inflammatory dermatosis commonly associated with mucosal involvement.
What is the possible pathogenesis behind lichen planus?
T-cell driven reaction
How does lichen planus present histologically?
Hyperkeratosis with thickening of granular cell layer
Dense T-cell infiltrate at the DEJ - becomes ragged and saw-toothed
Basal layer shows liquefactive degeneration with colloid bodies in the upper dermis.
What is acanthosis?
Diffuse epidermal hyperplasia
What is hyperkeratosis?
is thickening of the stratum corneum (keratin layer)
What is hyperkeratosis?
is thickening of the stratum corneum (keratin layer)
How does lichen planus present?
Small, purple, flat-topped, polygonal papules
Intensely itchy
Common on wrist flexors and lower legs
May be a fine, white, lacy pattern on lesion surface
Lesions often localise themselves to scratch marks
How may lichen planus present in an individual with pigmented skin?
lesions fuse into plaques
Hyperpigmentation
How might lichen planus present on the scalp?
Scarring alopecia
If lichen planus involves the mucousal surfaces, how dies this present?
Lacy, white streaks or ulceration or white plaques
Severe pain
How can lichen planus affect the nails?
Dystophy
May be lost all together in severe disease
How can lichen planus affect the nails?
Dystophy
May be lost all together in severe disease
What is the prognosis of lichen planus?
Often clears after 18 months but can reccur
Hypertrophic, atrophic and mucosal-involving varients are more persistent and may last for years
Ulcerative mucosal disease is pre-malignant
How is lichen planus treated?
Potent topical steroid
How is lichen planus treated?
Potent topical steroids and sometimes oral prednisolone
Oral lesions need high potency steroids given as a gel, ointment or mouth wash
Resistant cases may respond to PUVA, oral retinoids or azathioprine
Topical 0.1% tacrolimus ointment or pimecrolimus is v. useful in oral disease that has not responded to steroids
Although the cause of acne vulgaris is multifactorial, what critical factors play a part in the pathological process?
Follicular epidermal hyperproliferation
Blockage of pilosebaceous units with surrounding inflammation
Increased sebum production
Infection with Propionbacterium acnes.
How does infection with propionbacterium bacterium cause inflammation?
Activates Toll-like receptor 2, leading to production of pro-inflammatory cytokines
Where does acne vulgaris present on the body?
Areas rich in sebaceous glands such as the face, back and sternal area
What are the 3 cardinal features of acne vulgaris?
Open comedones (blackheads) or closed comedones (whiteheads
Inflammatory papules
Pustules
If inflammed acne lesions rupture what can this cause?
Deep-seated dermal inflammation
If inflammed acne lesions rupture what can this cause?
Deep-seated dermal inflammation
What is infantile acne?
Facial acne in infants, which may be cystic
Thought to be due to maternal androgens
Resolves spontaneously
What is steroid acne?
Acne which occurs secondary to corticosteroid therapy or Cushing’s syndrome
Often appears as a pustular folliculitis on the trunk without comedomes
What is oil acne?
An industrial disease seen in workers who have prolonged contact with oils or other hydrocarbons
Common on the legs and other exposed sites
What is acne fulminans?
A rare variant commonly seen in young male adolescents
A severe, necrotic, crusted acne associated with malaise, pyrexia, arthralgia and bone pain
How is acne fulminans treated?
Urgent oral prednisolone and analgesics followed by a course of oral isotretinoin
What is acne conglobata?
A cystic acne with abscesses and interconnecting sinuses
What is acne excoriee?
A deeply excoriated and picked acne with associated scarring
Much more common in females
What is the follicular occlusion Triad
A rare disorder most commonly seen in black Africans
Characterised by the presence of severe nodulocystic acne, dissecting cellulitis of the scalp and hidradentis suppurativa
May be caused by a problem with follicular occlusion
What are the 1st line agents used in acne treatment?
Topical keratolytics/topical retinoids/ retinoid-like agents
Topical antibiotics for inflammatory acne
What is the 2nd line therapy for acne treatment?
Low dose oxytetracycline for 3-4 months minimum
Cyproterone acetate - contraceptive pill with anti-androgen activity
What is the 2nd line therapy for acne treatment?
Low dose oxytetracycline for 3-4 months minimum
Cyproterone acetate - contraceptive pill with anti-androgen activity
What 3rd line therapy is available for use in acne treatment?
Oral retinoids (isotretinoin)
What are the indications for using 3rd line acne therapy?
If 1st and 2nd line treatments have been tried and have failed
Nodulocystic acne with scarring
Severe psychological disturbance
What are retinoids?
Synthetic Vit A analogues which affect cell growth and differentiation
What adverse effects do retinoids have?
V. teratogenic
Hair thinning
Myalgia
Dry skin
How effective are retinoids?
> 90% will respond to therapy
65% will obtain a long term “cure”
What needs to be carefully monitored while using retinoids?
Blood count
Liver biochemistry
Fasting lipids
What is rosacea?
A common inflammatory rash predominently affecting the face
Onset is usually middle age and ommoner in women
Often causes significant psychological distress
What is the suggested pathogenesis behind rosacea?
An underlying problem in the vasomotor stability of blood vessels
A possible role of the skin mite dermodex
How does rosacea present clinically?
Facial flushing with inflammatory papules and pustules affecting the nose. forehead and cheeks
No comedomes
Dilated blood vessels, inflammation of the eyelid margins, keratitis and sebaceous gland hypertrophy (nose) can also occur
What may exacerbate flushing in rosacea?
Alcohol Hot drinks Sunlight Changes in the ambient temperature Steroids may also exacerbate or trigger the condition
How is rosacea treated?
Long term use of topical metronidazole or topical azelaic acid
3 months of oral tetracycline may be useful
Cosmetic camouflage
Resistant cases may require oral metronidazole or isotretinoin
What is perioral dermatitis?
A common rash which occurs around the mouth (esp. in young females)
Often has an iatrogenic component from an exacerbation from topical steroids
Exact cause is unknown
How does perioral dermatits present?
Erythema, scaling, papules and occasionally pustules around the mouth
Usually spares a halo of skin immediately around the lips
How is perioral dermatitis treated?
Stopping of topical steroids
3-4 month course of low-dose oxytertracycline or erythromycin and topical metronidazole
How is perioral dermatitis treated?
Stopping of topical steroids
3-4 month course of low-dose oxytertracycline or erythromycin and topical metronidazole
What happens in porphyria cutanea tarda (PCT)?
A bullous eruption on exposure to sunlight which heals with scarring
What can precipitate PCT?
Alcohol
Hep C
HIV
Liver disease (tumours)
How is PCT diagnosed?
With the presence of increased urinary uroporhyrin
How does PCT present histologically?
Sub-epidermal blisters with perivascular deposition or periodic acid-Schiff-staining material
How is PCT treated?
Treat the underlying diseases and relieving the skin disease
What is erythropoietic poriotoporphyria (EPP)?
Irritation and burning pain in the skin on exposure to sunlight
Potential protoporphyrin deposition in the liver
How is EPP diagnosed?
Fluorescence of the peripheral RBCs and by increased protoporphyrin present in RBCs and stools
How are acute attacks of photocutaneous porphyrias treated?
Symptomatic treatment
Venesection to reduce urinary porphyria in PCT
Chloroquine to aid uroporphyrin excretion in PCT
Liver transplantation may be needed in severe cases
How are attacks of photocutaneous porphyrias prevented?
Avoidance of sunlight
Use of zinc-containing suncreams
Oral beta-caroten provides effective protection against solar sensitivity in EPP
What is phototherapy used for?
UVB and UVA both have a suppressive effect on cutaneous inflammation and may suppress systemic immunoreactivity
What are the disadvantages of phototherapy?
Skin aging
May predispose to malignancy of skin (UVB less carcinogenic)
UVA must be used alongisde what to be effective?
A photosensitisor agent (PUVA)
UVA must be used alongisde what to be effective?
A photosensitisor agent (PUVA)
What is a polymorphic light eruption (PLE)?
The most common photosentitive eruption in temperate regions affecting 10-20% of the population
Most common in young women
How does PLE present?
Itchy rash after exposure to sunlight, lesions may be papules, vesicles or plaques
May last for hours-days
Starts in spring and improves in summer due to skin ‘hardening’
How is PLE treated?
Avoidance of sunlight and use of sunblocks
Topical steroids help during a attack
Oral prednisolone may prevent or treat an attack caused by intense sun exposure
Resistant cases may requires desensitisation with PUVA
What is solar urticaria?
An extremely rare condition where itchy urticarial lesions occur within minutes of sun exposure and settle after 1-2 hours
How is solar urticaria treated?
Sun avoidance
Sunblocks
H1 antihistamines
Low dose phototherapy
What is pemphigus vulgaris?
A potentially fatal blistering disease occuring in all races
Onset is usually in middle age and there is no gender preference
What is the pathogenesis behind pemphigus vulgaris?
Autoantibodies against desmosomal protein desmoglein 1+3 (expressed in skin and mucosal sufaces)
Autoantibodies can bemeasured as markers of disease activity
What does skin biopsy show in pemphigus vulgaris?
A superficial intraepidermal split just above the basal layer with acantholysis (separation of individual cells)
How does pemphigus vulgaris present clinically?
Mucosal involvement - oral ulceration is the presenting sign in ~50% cases
This may be followed by non-itchy flaccid (loose) blisters esp on the trunk
Blistering ususally becomes widespread but they rapidly denude (burst)
Thus pemphigus often presents with erythematous, weeping erosions
How does pemphigus vulgaris present clinically?
Mucosal involvement - oral ulceration is the presenting sign in ~50% cases
This may be followed by non-itchy flaccid (loose) blisters esp on the trunk
Blistering ususally becomes widespread but they rapidly denude (burst)
Thus pemphigus often presents with erythematous, weeping erosions
Flexural lesions have a vegetative appearance
What is Nikolsky’s sign?
Extension of blisters by gentle sliding pressure
How is pemphigus vulgaris treated?
High-dose oral prednisolone or pulsed methylprednisolone which is often needed for life
Other immunosupressive agents e.g. azathioprine or mycophenolate mofetil
The anti-B-cell drug rituximab is useful in resistant cases
IV immunoglobulin covers the lag phase of other treatments
What is the prognosis of pemphigus vulgaris?
Treatment is usually effective but upto 10% of patients die from disease complications or treatment side-effects
What is bullous pemphigoid?
A more common condition than pemphigus which presents later in life and mucosal involvement is rarer
What is bullous pemphigoid?
A more common condition than pemphigus which presents later in life and mucosal involvement is rarer
What does skin biopsy show in bullous pemphigoid?
A deeper blister due to a subepidermal split through the basement membrane
What does skin biopsy show in bullous pemphigoid?
A deeper blister due to a subepidermal split through the basement membrane
What do immunoflourescence (IMF) studies show in Bullous pemphigoid?
Linear staining of IgG along the basement membrane
What do IMF studies show in pemphigus valgaris?
IgG intracellular staining is within the epidermis
How does bullous pemphigoid present?
Large, tense bullae appear anywhere on the skin
May be centered on an erythematous or urticated background and they may be haemorrhagic
May be v. itchy
How is bullous pemphigoid treated?
High dose oral prednisolone and steroid sparing agents e.g. azathioprine or mycophenolate mofetil
Often treatment can be withdrawn after 2-3 years
Side effects of medication is common esp. as most sufferers are elderly
How is a localised or mild version of bullous pemphigoid controlled?
Super potent topical steroids, oral dapsone or high dose oral minocycline
What is dermatitis herpetiformis
A rare blistering disease associated with coeliac disease
What does a skin biopsy of dermatitis herpetiformis show?
Subepidermal blister with neutrophil microabscesses in the dermal papillae
What do IMF studies show in dermatitis herpetiformis?
IgA in the dermal papillae and patchy granular IgA along the basement membrane
What would the jejunal mucosa show in an individual with dermatitis herpitiformis?
A partial villous atrophy
How does dermatitis herpetiformis present clinically?
Small, intensely itchy blisters on the skin esp. on the elbows, extensor forearms, scalp and buttocks
Tops of blisters are usually scratched off thus crusted erosions are seen at presentation
Remissions and exacerbations are common
How does dermatitis herpetiformis present clinically?
Small, intensely itchy blisters on the skin esp. on the elbows, extensor forearms, scalp and buttocks
Tops of blisters are usually scratched off thus crusted erosions are seen at presentation
Remissions and exacerbations are common
How is dermatitis herpetiformis treated?
GF diet
Oral dapsone or sulphonamides
Oral meds can be removed if strict GF diet is adhered to
What are the side effects of dapsone?
Frequently causes a mild dose-related haemolytic anaemia
Liver damage, peripheral neuropathy and aplastic anaemia are rarer complications
What must be monitored regularly when using dapsone?
Blood count
LFTs
What are melanocytic naevi?
Moles
Benign overgrowths of melanocytes, common in white-skinned individuals
Appear in childhood and increase in number and size during adolescence and early adulthood
How do melanocytic naevi change over time?
Often start as flat brown macules with melanocytic proliferation at the DEJ (junctional naevi)
Continue to proliferate and grow down into the dermis (compound naevi) and this causes elevation of the mole above the skin surface
Pigmentation is usually even and the border is smooth
They eventually mature into a dermal naevus (cellular naevus) often with a loss of pigment
What are blue naevi?
Acquired asymptomatic blue-looking moles
Forms from proliferation of melanocytes deep in the mid-dermis
Consist of pigment rich, dendritic spindle cells
What are halo naevi?
Naevi with a halo of depigmentation peripherally
Show inflammatiry regression and are overrun by lymphocytes
What is a naevus splius?
A skin lesion presenting with a light brown or tan maccule, which is speckled with smaller, darker maccules or papules
What is a Spitz naevus?
Usually occurs in those less than 20
Consists of large spindle/epithelioid cells
Closely mimics melanoma
Vast majority are entirely benign but there is a malignant varient
Lesions are pink due to prominent vasculature
Epidermal hyperplasia seen on histology
What is a basal cell papilloma?
A common benign overgrowth of the epidermal basal cell layer
May be flesh coloured, brown or black, often looks greasy (choc chip cookie appearance)
Surface is irregular, warty and lesions appear very superficial as though just stuck onto the skin
How are basal cell papillomas treated?
Cryotherapy or curettage
What is a dermatofibroma?
A firm, elevated, pigmented nodule which feels like a button in the skin. Peripheral ring of pigmentation sometimes seen.
Often found on legs
May be a preceding history of trauma or insect bite
Lesion consists of histiocytes, blood vessels and varying degrees of fibrosis
If symptomatic, excision required
What is a dermatofibroma?
A firm, elevated, pigmented nodule which feels like a button in the skin. Peripheral ring of pigmentation sometimes seen.
Often found on legs
May be a preceding history of trauma or insect bite
Lesion consists of histiocytes, blood vessels and varying degrees of fibrosis
If symptomatic, excision required
What is seborrhoeic keratosis?
More or less the same as a basal cell papilloma
V.common in aging skin esp. on the face and trunk
Histologically shows epidermal acanthosis, hyperkeratosis and horn cysts
An eruptive appearance of many lesions may indicate an internal malignancy (Leser-Trelat sign)
What are ephilides?
Freckles!
A patchy increase in melanin pigmentation which occurs after UV exposure
Reflects a clumpy distribution of melanocytes
What is keratoacanthoma?
A rapidly growing epidermal tumour which develops central necrosis and ulceration
Occurs on sun exposed skin in later lifeand may grow to 2-3cm diameter
May resolve spontaneously over a few months
Better to be excised to exclude a squamous cell carcinoma, which they can mimic, and also this improves the cosmetic outcome
What is a cherry angioma?
Benign angiokeratoma that appears as tiny pin-point papules esp. on trunk
Increase in frequency with age
No treatment is required
What are solar keratoses (actinickeratoses)
Frequently develop in later life in white-skinned individuals with significant sun exposure
Appear on skin as erythematous, silver-scaly papules or patches with a conical surface and a red base
Background skin is often inelastic, wrinkled and may show flat, brown macules (solar lentigos) reflecting diffuse solar damage
What may happen to a small proportion of solar keratoses after being present for many years?
Turn into SCCs
How are solar keratoses treated?
Cryotherapy
Topical 5-fluorouracil crsm
5% imiquimad cream
Diclofenac gel
What is Bowen’s disease?
A form of carcinoma-in-situ which may rarely become invasive
Thought to be due to long term sun exposure
What is Bowen’s disease?
A form of carcinoma-in-situ which may rarely become invasive
Thought to be due to long term sun exposure
Commoner in immunospressed individuals
How does Bowens disease present?
Isolated, scaly, red patch or plaque similar to psoriasis but with a v. irregular border
Lesions slowly increase in size with time
May involve epidermis of the mucosa or neighbouring skin
Nonspecific erythema or a warty thickening
What areas of the body does Bowen’s disease commonly affect?
Sun exposed areas esp. womens legs
Also vulva, glans penis and perianal skin
What disease is linked to Bowen’s disease?
HPV infection - higher pre-malignant potential
How is Bowen’s disease treated?
Topical 5-flurouracil 5% imiquimod cream Cryotherapy Curettage Photodynamic therapy Tissue-destructive laser
What is atypical mole syndrome (dysplastic naevus syndrome)?
A large number of melanocytic naevi begin to appear in childhood even in unexposed sites
Individual lesions may be large with irregular pigmentation on border
How does dysplstic naevus syndrome appear histologically?
May show cytological and architechtural atypia, but no frank malignant change
What should individuals with dysplastic naevus syndrome be aware of?
They have an increased risk of developing malignant melanoma
Should have their moles photographed and regulary reviewed
Suspicious lesions should be excised?
What should individuals with dysplastic naevus syndrome be aware of?
They have an increased risk of developing malignant melanoma
Should have their moles photographed and regulary reviewed
Suspicious lesions should be excised?
What is a giant congenital melanocytic naevi?
A very large mole present at birth
V. large lesions >20cm show increased risk of developing malignant melanoma
How are giant congenital melanocytic naevi managed?
Excision is considered but the cosmetic appearance is often not worth it
Regular monitoring
A few will improve spontaneously or partially resolve during childhood
What is lentigo maligna?
A slow-growing macular area of pigmentation seen in elderly people, commonly on the face
Border and pigmentation is often irregular
Increased risk of developing a malignant melanoma
What is the treatment for lentigo maligna?
Excision if possible
5% imiquimod cream tried in lesions where excision would be disfiguring
What is a basal cell carcinoma (BCC)?
The most common malignant type of skin tumour.
Common in the elderly population in exposed sites
How does a BCC present?
A slow-growing papule or nodule which may go on to ulcerate
Telangiectasia over the tumour or a skin-coloured jelly-like pearly edge may be seen
It grows slowly and erodes structures if left untreated but almost never metastasises
How is a BCC treated?
Usually with surgical excision
Phototherapy, cryotherapy and 5%imiquimod cream can be used as adjuncts to surgery
What is a squamous cell carcinoma (SCC)?
A more aggressive malignant tumour than BCC, mostly related directly to sun exposure
What conditions may be associated with development of SCC?
Solar keratoses
Bowen’s disease
Lupus vulgaris - chronic inflammation
How does SCC present clinically?
Lesions are often keratotic, ill-defined nodules that may ulcerate.
May grow v. rapidly
How are SCCs treated?
Excision or occasionally radiotherapy
Curettage should be AVOIDED
How are SCCs treated?
Excision or occasionally radiotherapy
Curettage should be AVOIDED
What is malignant melanoma?
The most serious form of skin cancer, where metastases occur early and death is possible even in young people
What predisposed an individual to developing a malignant melanoma?
Excessive sunlight exposure Pale skin Sun sensitivity Multiple melanocytic naevi (>50) Immunosuppression Dysplastic naevi syndrome Lentigo maligna \+ve FH
What are the 4 clinical types of malignant melanoma?
Lentigo maligna melanoma
Superficially spreading malignant melanoma
Nodular Malignant melanoma
Acral lentiginous malignant melanoma
How does lentigo maligna melanoma present?
A patch of lentigo maligna develops a papule or nodule, signalling an invasive tumour
How does a superficially spreading malignant melanoma present?
A large, flat, irregularly pigmented lesion which grows laterally before vertical invasion occurs
How does a nodular malignant melanoma present?
Most aggressive type
Rapidly growing, pigmented nodule which bleeds or ulcerates
Rarely they are amelanotic and mimic pyogenic granuloma
How does acral lentiginous malignant melanoma present?
Pigmented lesions on the palm, soles or under the nail
Usually present late
May not be related to sun exposure
What is the treatment for malignant melanoma?
Surgery is the only curative treatment with surgical margins
What does the prognosis of malignant melanoma dependant on?
Breslow Thickness
What is the prognosis for pTis?
Melanoma in situ
100% 5 year survival
What is the prognosis for pT1?
Tumour less than 1mm deep
90% 5 year survival
What is the prognosis for pT2?
Tumour 1-2mm deep
80% 5 year survival
What is the prognosis for pT3?
Tumour 2-4mm deep
55% 5 year survival
What is the prognosis for pT4?
Tumour >4mm deep
20% 5 year survival
What is the prognosis for pT4?
Tumour >4mm deep
20% 5 year survival
What is Cutaneous T-cell lymphoma?
A rare skin tumour which often follows a fairly benign course
How does Cutaneous T-cell lymphoma present?
Scaly patches and plaques which may resemble eczema or psoriasis
Lesions often appear on the buttocks and these may come and go for many years
Occasionally disease can progress to a cutaneous nodular, or tumour stage
What would a skin biopsy of a Cutaneous T-cell lymphoma show?
Invasion by atypical lymphocytes
How is Cutaneous T-cell lymphoma treated?
Early disease = watch and wait, topical steroids, PUVA
Advanced disease = radiotherapy, oral retinoids, chemo, immunotherapy or electron beam therapy
What are venous ulcers?
The result of sustained venous hypertension in the superficial veins
Increased pressure caused extravasation of fibrinogen through the capillary walls giving rise to perivascular fibrin deposition, leading to poor oxygenation of the surrounding skin
Where do venous ulcers commonly present?
On the lower leg in a triangle above the ankles
What clinical features may be associated with venous ulceration?
Oedema of lower legs
Venous eczema
Brown pigmentation from haemosiderin
Varicose veins
Lipodermatosclerosis - a fibrosing panniculitis of the subcut. tissue
Scarring white atrophy with telangiectasia (atrophie blanche)
What is panniculitis?
Inflammation of subcutaneous adipose tissue
How are venous ulcers treated?
High-compression bandaging Leg elevation Doppler studies to exclude arterial disease Ulcer dressings Diuretics Analgesia Lifelong support stockings
How are venous ulcers treated?
High-compression bandaging Leg elevation Doppler studies to exclude arterial disease Ulcer dressings Diuretics Analgesia Lifelong support stockings
What are arterial ulcers?
Punched-out, painful ulcers, higher on the leg or on the foot
What can predispose an individual to an arterial ulcer?
Claudication in history
Hypertension
Angina
Amoking
How does the leg present clinically with arterial ulceration?
Cold and pale
Absent peripheral pulses
Arterial bruits
Loss of hair may also be present
How is arterial disease confirmed when faced with a leg ulcer?
Doppler studies
How are arterial ulcers treated?
Keep ulcer clean and covered
Analgesia
Vascular reconstruction is needed
Compression bandaging must NOT be used
What are pressure sores?
Skin ischaemia from sustained pressure over a bony prominence (heel and sacrum) in patients who are immobile.
What is a stage 1 pressure sore?
Non-blanchable erythema of intact skin
What is a stage 2 pressure sore?
Partial-thickness skin loss of epidermis/dermis
What is a stage 3 pressure sore?
Full-thickness skin loss involving subcut. tissue but not fascia
What is a stage 4 pressure sore?
Full-thickness skin loss with involvement of muscle/bone/tendon/joint capsule
How are pressure sores prevented?
Specialist tissue-viability nurses identify at risk patients and train other clinical staff
Risk assessment
How are pressure sores prevented?
Specialist tissue-viability nurses identify at risk patients and train other clinical staff
Risk assessment
How are pressure sores treated?
Best rest with pillows and fleeces to keep pressure off bony areas
Air-filled cushions for those in wheelchairs
Pressure-relieving mattresses and beds
Regular turning
Adequate nutrition
Non-irritant, occlusive, moist dressings
Analgesia
What is vasculitis?
An inflammatory disorder of the blood vessels which causes endothelial damage
What are the cutaneous features of vasculitis?
Haemorrhagic papules, pustules, nodules or plaques which may erode and ulcerate
Lesions do not blanche with pressure
What is lymphoedema?
A chronic non-pitting oedema due to lymphatis insufficiency which most commonly affects the legs and progresses with age
How does lymphoedema present?
Chronic disease may cause a ‘cobblestine’ thickening of the skin
How can lymphoedema occur?
Primary disease due to an inheriteddeficiency of lymphatic vessels
Secondary due to obstruction of lymphatuc vessels
How is lymphoedema treated?
Compression stockings and physical massage
If recurrent cellulitis then long-term antibiotics are advised so lymph vessels do not become damaged
What is lymphangioma Circumscription?
A rare haematoma of lymphatic tissue that presents in childhood with multiple small vesicles in the skin which weep lymphatic fluid and sometimes blood
Reflects deeper vessel involvement so surgery should be avoided
How should lymphangioma circumscription be treated?
Cryotherapy
CO2 laser treatments
What is vitiligo?
A common AI disease of depigmentation due to areas of melanocyte loss which presents in childhood or early adulthood
What is vitiligo?
A common AI disease of depigmentation due to areas of melanocyte loss which presents in childhood or early adulthood
How may vitiligo present?
Symmetrical lesions frequently involving the hace, hands and genitallia
Hair can also depigment
Trauma may induce new lesions
Spontaneous repigmentation may occur but this is rare
How is vitiligo treated?
Suncreams to avoid burning
Tacrolimus ointment on face
Potent topical steroids or phototherapy may help
Monobenzone if widespread
Referral to a specialist camouflage clinic
What is post-inflammatory hypopigmentation?
One of the most common causes of paled skin
May be seen as a consequence of other skin disease
If skin disease is controlled then pigmentation returns to normal over months
Post-inflammatory HYPER-pigmentation can also occur
What is oculocutaneous albinism?
A group of rare autosomal recessive disorders which affects the pigmentation of skin, hair and eyes.
Melanocytes are normal in number but have abnormal function
How does oculocutaneous albinism present?
Universal pale skin, white or yellow hair, pinkish iris
Photophobia, nystagmus, squint are also present in most cases
How is oculocutaneous albinism treated?
Obsessive protection against sunlight
What is idiopathic guttate hypomelanosis?
Occurs most often in black African people with small asymptomatic porcelain-white macules on skin exposed to sunlight
No effective treatment
How can leprosy affect skin pigmentation?
Both tuberculoid and intermediate leprosies present with anaesthetic patches of depigmentation
Also loss of hair and decreased sweating
What conditions are common causes of hyperpigmentation?
Freckles Lentigos Cholasma Metabolic/endocrine effects Peutz-Jeghers disease Urticaria pigmentosa Cafe-au-lait macules Multiple lentigines Acquired melanocytic naevi
What are lentigos?
A more permanant macule of pigmentation similar to freckles but often present in the winter Solar lentigos (liver spots) occur in older people on exposed skin due to actinic damage
What are lentigos?
A more permanant macule of pigmentation similar to freckles but often present in the winter Solar lentigos (liver spots) occur in older people on exposed skin due to actinic damage
What is cholasma?
Brown macules seen symmetrically over the cheeks and forehead
May be spontaneous but may also occur in pregnancy and in individuals taking the oral contraceptive
What metabolic/endocrine effects can cause hyperpigmentation of skin?
Chronic liver disease esp. haemochromatosis
Cushing’s syndrome
Addison’s disease
Nelson’s syndrome
What is Peutz-Jeghers syndrome?
An autosomal dominant condition which presents with brown macules on the lips and perioral region
Associated with GI polyposis
What is urticaria pigmentosa?
Multiple pigmented macule sin children which become red,itchy and urticated if rubbed
Resolves spontaneously in children but does not if condition begins in adulthood
What would a skin biopsy of urticaria pigmentosa show?
Excess of mast cells in the skin
How is urticaria pigmentosa treated?
Antihistamines
Sodium cromoglicate or PUVA
What are cafe-au-lait molecules seen in?
NF 1+2 Tuberculosclerosis Ataxia Telangiectasia MEN1
In what conditions are multiple lentigines seen?
Peutz-Jeghers syndrome
Xeroderma pigmentosum
LEOPARD syndrome
What is LEOPARD syndrome?
L - Lentigines E - ECG conduction abnormalities O - Ocular hypertelorism P - Pulmonary stenosis A - Abnormalities of genitallia R - Retardation of growth D - Deafness
In what conditions are acquired melanocyic naevi seen?
Tuner’s syndrome
Atypical mole syndrome
What is toxic epidermal necrosis (TEN)?
A widespread subepidermal blistering and sloughing of >30% of the skin
How does TEN present?
Cough, myalgia and poor appetite may precedes skin signs by 2-3 days
Skin may itch but typically burns
Fever and mucosal involvement common
Multiorgan involvement and sepsis often occurs
How is TEN treated?
A specialist burns unit or ICU
Occlusive cutaneous dressings give significantly reduced pain
What is drug-induced hypersensitivity syndrome (DHS)?
A serious adverse systemic reaction to a drug occuring 2-6 weeks after the initial exposure
How does DHS present?
Generalised mucocutaneous rash Fever Lymphadenopathy Arthralgia Pharyngitis Periorbital oedema Hepatoslenomegaly
What may blood show when examined in DHS?
Peripheral eosinophillia
Lymphocytosis with atypical lymphocytes
What is a common culprit of DHS?
Aromatic anticonvulsants
How is DHS treated?
Drug withdrawal
Systemic steroids
Supportive care
How is DHS treated?
Drug withdrawal
Systemic steroids
Supportive care
What diseases can cause nail pitting?
Psoriasis
Alopecia areta
Atopic eczema
Trauma
What conditions can cause onchylosis?
Psoriasis
Thyrotoxicosis
Trauma
What diseases can cause Koilonychia?
Iron deficeincy anaemia
Congenital - rare
What conditions can cause Leuconycia?
Hypoalbuminaemia
What diseases can cause Beau’s lines?
Severe illness or shock
What causes Yellow nail syndrome?
Rare disorder of lymphatic drainage
Pleural effusions, bronchiectasis and nail lymphoedema
What can cause onychogryphosis?
Trauma
Psoriasis
Fungal infection
What is androgenic alopecia?
The most common type of non-scarring hair loss
Male pattern baldness
What is alopeica areata?
An AI-mediated type of hair loss associated with other organ specific AI diseases
Children or young adults
What is a cream?
A semisolid mixture of oil and water, held together by an emulsifying agent
Have high cosmetic acceptability
What is an ointment?
A semisolid containing no water and based purely on oils or greases.
Feel greasy or sticky to touch
What are lotions?
Water-based or alcohol-based substance which provides a cooling effect on the skin
What are gels?
Semisolid preparations of high molecular weight polymers
What are pastes?
Contain a high % powder in an ointment base
